The impact of prenatal care on postneonatal deaths in the presence and absence of antenatal high-risk conditions

OBJECTIVE: This study was undertaken to determine the association, if any, between prenatal care and postneonatal death in the presence and absence of high-risk pregnancy conditions. STUDY DESIGN: Data were derived from the national linked birth/infant death data set for the years 1995 to 1997 provided by the National Center for Health Statistics. Analyses were restricted to singleton live births that occurred after 23 completed weeks of gestation. Multiple births, congenital malformations, chromosomal abnormalities, missing data on gestational age, and birth weight less than 500 g were excluded. Multivariable logistic regression analyses were used to adjust for various antenatal high-risk conditions, maternal age, gravidity, gestational age at delivery, birth weight, maternal education, marital status, smoking, and alcohol use. Postneonatal death rate was defined as the number of deaths between 28 and 365 days of life per 1,000 neonatal survivors. RESULTS: For 10,512,269 singleton live births analyzed, 21,962 (2.1 per 1,000) resulted in postneonatal death. Postneonatal death rates were higher for African American women than white women in the presence (3.8 vs 1.7 per 1,000) and absence (11.2 vs 5.3 per 1,000) of prenatal care. Lack of prenatal care was associated with increased relative risk (RR) for postneonatal death, 1.8-fold in African American women and 1.6-fold in white women. Lack of prenatal care was associated with increased postneonatal death rates to a similar degree for the individual high-risk pregnancy conditions for both African American and white women. Lack of prenatal care was associated with increased postneonatal death rates, especially in the presence of postterm pregnancy (RR 2.3, 95% CI 1.6, 3.1), pregnancy-induced hypertension (RR 2.2, 95% CI 1.5, 3.4), intrapartum fever (RR 2.1, 95% CI 1.2, 3.5), and small-for-gestational-age infant (RR 1.6, 95% CI 1.3, 2.0). CONCLUSION: Lack of prenatal care should be considered as a high-risk factor for postneonatal death for both African American and white women, especially if the pregnancy has been complicated by postdates, pregnancy-induced hypertension, intrapartum fever or small-for-gestational-age infant.     

The effect of placenta previa on neonatal mortality: a population-based study in the United States, 1989 through 1997

OBJECTIVE: The purpose of the study was to explore the associations of placenta previa with preterm delivery, growth restriction, and neonatal survival. STUDY DESIGN: A retrospective cohort study was performed of live births in the United States (1989-1991 and 1995-1997) that used the national linked birth/infant death records from 22,368,235 singleton pregnancies. The diagnosis of previa was restricted to those live births that were delivered (> or =24 weeks) by cesarean delivery. We evaluated gestational age and birth weight-specific risk of neonatal deaths (within the first 28 days) in relation to placenta previa. Fetal growth was assessed in centiles of birth weight (<3rd, 3rd-4th, 5th-9th, 10th-90th, and >90th centile), adjusted for gestational age. All analyses were adjusted for the confounding effects of the year of delivery, maternal age, gravidity, education, prenatal care, marital status, and race/ethnicity. RESULTS: Placenta previa was recorded in 2.8 per 1000 live births (n = 61,711). Neonatal mortality rate was 10.7 with previa, compared with 2.5 per 1,000 among other pregnancies (relative risk, 4.3; 95% confidence interval, 4.0,4.8). At 28 to 36 weeks, babies born to women with placenta previa weighed, on average, 210 g lower than babies born to women without placenta previa (P <.001). Compared with babies born to women without previa, the risk of death from placenta previa was lower among preterm babies (<37 weeks of gestation), with a crossover at 37 weeks where the mortality rate was higher for babies born to women with placenta previa than for babies born to women without placenta previa. This crossover also persisted in an analysis by birth weight and term births (delivered at > or =37 weeks of gestation). Mortality rates for term births were higher among babies born to women with placenta previa than among babies born women without placenta previa who were at the 10th to 90th centile (relative risk, 1.9; 95% confidence interval, 1.3, 2.8), and those at >90th centile (relative risk, 3.6; 95% confidence interval, 1.3, 9.6). Among preterm births, however, placenta previa was not associated with increased neonatal mortality by fetal growth centiles. CONCLUSION: The risk of neonatal mortality was higher for babies born to women with placenta previa than for babies born to women without placenta previa who were delivered at > or =37 weeks of gestation. Pregnancies that are diagnosed with placenta previa must be monitored carefully, especially as they approach term.     

The impact of prenatal care in the United States on preterm births in the presence and absence of antenatal high-risk conditions

OBJECTIVE: This study was undertaken to determine the association between prenatal care in the United States and preterm birth rate in the presence, as well as absence, of high-risk pregnancy conditions for African American and white women. STUDY DESIGN: Data were derived from the natality data set for the years 1995 to 1998 provided by the National Center for Health Statistics. Analyses were restricted to singleton live births that occurred at >/=20 weeks' gestation. Multiple births, fetal deaths, congenital malformations, chromosomal abnormalities, missing data on gestational age, and birth weight less than 500 g were excluded. Multivariable logistic regression analyses were used to adjust for the presence or absence of various antenatal high-risk conditions, maternal age, gravidity, marital status, smoking, alcohol, and education. Prenatal care was considered present if there was one or more prenatal visits. Preterm delivery was defined as delivery at less than 37 completed weeks of gestation. RESULTS: For 14,071,757 births analyzed, 1,348,643 (9.6%) resulted in preterm birth. Preterm birth rates were higher for African American women than white women in the presence (15.1% vs 8.3%) and absence (34.9% vs 21.9%) of prenatal care. The absence of prenatal care increased the relative risk for preterm birth 2.8-fold in both African American and white women. There was an inverse dose-response relationship between the number of prenatal visits and the gestational age at delivery both among African American and white women. Lack of prenatal care was associated with increased preterm birth rates to a similar degree in the presence of pregnancy complications for both African American and white women, ranging from 1.6-fold to 5.5-fold for the various antenatal high-risk conditions. CONCLUSION: In the United States, prenatal care is associated with fewer preterm births in the presence, as well as absence of high-risk conditions for both African American and white women. Strategies to increase prenatal care participation may decrease preterm birth rates.     

Placenta previa: neonatal death after live births in the United States

OBJECTIVE: The purpose of this study was to describe neonatal mortality rates among live births that were complicated by placenta previa in the United States. STUDY DESIGN: This was a population-based retrospective cohort study of 1997 United States singleton live births. Neonatal deaths among pregnancies that were complicated by placenta previa were compared with deaths among pregnancies with no placenta previa. Adjusted and unadjusted hazard ratios were generated from a proportional hazards regression model. RESULTS: Of 3,773,369 live births, 9656 were complicated by placenta previa (2.6 cases per 1000). Among cases of placenta previa, 114 neonatal deaths occurred (11.8 per 1000) versus 14951 (4 per 1000) among non-placenta previa neonates (P <.0001). The adjusted relative risk of death was three times higher among placenta previa neonates (hazard ratio, 3.06; 95% CI, 2.40-3.94). Placenta previa-related death was mediated through preterm delivery rather than small for gestational age. CONCLUSION: Placenta previa triples the rate of neonatal mortality, which is mediated mainly through preterm birth.     

Prenatal care and black-white fetal death disparity in the United States: heterogeneity by high-risk conditions

OBJECTIVE: To determine the impact of prenatal care in the United States on the fetal death rate in the presence and absence of obstetric and medical high-risk conditions, and to explore the role of these high risk conditions in contributing to the black-white disparity. METHODS: This is a population-based, retrospective cohort study using the national perinatal mortality data for 1995-1997 assembled by the National Center for Health Statistics. Fetal death rate (per 1000 births) and adjusted relative risks were derived from multivariable logistic regression models. RESULTS: Of 10,560,077 singleton births, 29,469 (2.8 per 1000) resulted in fetal death. Fetal death rates were higher for blacks than whites in the presence (4.2 versus 2.4 per 1000) and absence (17.2 versus 2.5 per 1000) of prenatal care. Lack of prenatal care increased the (adjusted) relative risk for fetal death 2.9-fold in blacks and 3.4-fold in whites. Blacks were 3.3 times more likely to have no prenatal care compared with whites. Over 20% of all fetal deaths were associated with growth restriction and placental abruption, both in the presence and absence of prenatal care. Lack of prenatal care was associated with increased fetal death rates for both blacks and whites in the presence and absence of high-risk conditions. CONCLUSION: In the Unites States, strategies to increase prenatal care participation, especially among blacks, are expected to decrease fetal death rates.     

Association of maternal fever during labor with neonatal and infant morbidity and mortality.

OBJECTIVE: To examine the association of intrapartum fever with infant morbidity and early neonatal (0-6 days) and infant (0-364 days) death. METHODS: We carried out a retrospective cohort analysis among singleton live births in the United States for the period 1995-1997 using the National Center for Health Statistics linked birth-infant death cohort data. RESULTS: Among the 11,246,042 singleton live births during the study period, intrapartum fever (at least 38C) was recorded in 1.6%. Intrapartum fever was associated with early neonatal (adjusted odds ratio [OR], 95% confidence interval [CI] for preterm and term infants respectively: 1.32; 1.11, 1.56 and 1.67; 1.14, 2.46) and infant (OR, 95% CI for preterm and term, respectively: 1.31; 1.14, 1.51 and 1.27; 1.01, 1.59) death among nulliparous mothers. Among preterm infants of parous mothers, intrapartum fever was associated with early neonatal (OR 1.29, 95% CI 1.01, 1.64) death. In the combined analyses (infants of nulliparous and parous mothers), intrapartum fever was a strong predictor of infection-related death. These associations were stronger among term (OR 3.16, 95% CI 1.56, 6.40 for early neonatal; OR 1.75, 95% CI 1.20, 2.57 for infant death) than preterm infants (OR 1.52, 95% CI 1.15, 2.00 for early neonatal; OR 1.29, 95% CI 1.05, 1.57 for infant death). Intrapartum fever was also a risk factor for meconium aspiration syndrome, hyaline membrane disease, neonatal seizures, and assisted ventilation. CONCLUSION: Intrapartum fever is an important predictor of neonatal morbidity and infection-related mortality.     

Incidence of stillbirth and perinatal mortality and their associated factors among women delivering at Harare Maternity Hospital, Zimbabwe: a cross-sectional retrospective analysis

BACKGROUND: Death of an infant in utero or at birth has always been a devastating experience for the mother and of concern in clinical practice. Infant mortality remains a challenge in the care of pregnant women worldwide, but particularly for developing countries and the need to understand contributory factors is crucial for addressing appropriate perinatal health. METHODS: Using information available in obstetric records for all deliveries (17,072 births) at Harare Maternity Hospital, Zimbabwe, we conducted a cross-sectional retrospective analysis of a one-year data, (1997-1998) to assess demographic and obstetric risk factors for stillbirth and early neonatal death. We estimated risk of stillbirth and early neonatal death for each potential risk factor. RESULTS: The annual frequency of stillbirth was 56 per 1,000 total births. Women delivering stillbirths and early neonatal deaths were less likely to receive prenatal care (adjusted relative risk [RR] = 2.54; 95% confidence intervals [CI] 2.19-2.94 and RR = 2.52; 95% CI 1.63-3.91), which for combined stillbirths and early neonatal deaths increased with increasing gestational age (Hazard Ratio [HR] = 3.98, HR = 7.49 at 28 and 40 weeks of gestation, respectively). Rural residence was associated with risk of infant dying in utero, (RR = 1.33; 95% CI 1.12-1.59), and the risk of death increased with increasing gestational age (HR = 1.04, HR = 1.69, at 28 and 40 weeks of gestation, respectively). Older maternal age was associated with risk of death (HR = 1.50; 95% CI 1.21-1.84). Stillbirths were less likely to be delivered by Cesarean section (RR = 0.64; 95% CI 0.51-0.79), but more likely to be delivered as breech (RR = 4.65; 95% CI 3.88-5.57, as were early neonatal deaths (RR = 3.38; 95% CI 1.64-6.96). CONCLUSION: The frequency of stillbirth, especially macerated, is high, 27 per 1000 total births. Early prenatal care could help reduce perinatal death linking the woman to the health care system, increasing the probability that she would seek timely emergency care that would reduce the likelihood of death of her infant in utero. Improved quality of obstetric care during labor and delivery may help reduce the number of fresh stillbirths and early neonatal deaths.     

Adverse perinatal outcomes among interracial couples in the United States

OBJECTIVE: We examined the association between parental race and stillbirth and adverse perinatal and infant outcomes. METHODS: We conducted a retrospective cohort analysis using the 1995-2001 linked birth and infant death files that are composed of live births and fetal and infant deaths in the United States. The study included singleton births delivered at 20 or more weeks of gestation with a fetus weighing 500 g or more (N = 21,005,786). Parental race was categorized as mother white-father white, mother white-father black, mother black-father white, and mother black-father black. Multivariable logistic regression analysis was performed to examine the association between parental race and risks of stillbirth (at > or = 20 weeks), small for gestational age (defined as birth weight < 5th and < 10th percentile for gestational age), and early neonatal (< 7 days), late neonatal (7-27 days), and postneonatal (28-364 days) mortality. All analyses were adjusted for the confounding effects of maternal age, education, trimester at which prenatal care began, parity, marital status, and smoking during pregnancy. RESULTS: Although risks varied across parental race categories, stillbirth was associated with a higher-than-expected risk for interracial couples: mother white-father black, relative risk (RR) 1.17 (95% confidence interval [CI] 1.10-1.26) and mother black-father white, RR 1.37 (95% CI 1.21-1.54) compared with mother white-father white parents. The RR for stillbirth was even higher among mother black-father black parents (RR 1.67, 95% CI 1.62-1.72). The overall patterns of association for small for gestational age births (< 5th and < 10th percentile) and early neonatal mortality were similar to those seen for stillbirth. CONCLUSION: There is an increased risk of adverse perinatal outcomes for interracial couples, including stillbirth, small for gestational age infants, and neonatal mortality. LEVEL OF EVIDENCE: II-2.     

Effect of labor on infant morbidity and mortality with preterm premature rupture of membranes: United States population-based study

OBJECTIVE: To evaluate whether labor, in the setting of premature rupture of membranes (PROM), affects infant morbidity and mortality rates. METHODS: We derived data for this population-based cohort study from the United States national linked birth infant death data sets, comprised of singleton live births delivered between 1995 and 1997. We included women (n = 34,594) who had preterm PROM more than 12 hours and delivered between 23 and 32 weeks' gestation. Birth records were used to determine whether delivery occurred with or without labor. Infants with birth weights below the tenth percentile for gestational age were classified as small for gestational age (SGA) on the basis of a nomogram of all singleton births in the United States between 1995 and 1997. Primary outcomes were early neonatal (0-6 days), late neonatal (7-27 days), postneonatal (28-365 days), and infant death (0-365 days). Secondary outcomes included respiratory distress syndrome (RDS), assisted ventilation, and neonatal seizures. Risks of infant mortality and morbidity from labor were examined separately for SGA and non-SGA infants. RESULTS: Overall rates were infant death 11.6%, RDS 15.1%, assisted ventilation 25.9%, and neonatal seizure 0.2%. Labor was associated with higher incidence of early neonatal death in SGA infants (adjusted relative risk [RR] 1.24, 95% confidence interval [CI] 1.11, 1.38) but had no effect on other outcomes. Among non-SGA infants, labor had no effect on infant death but was associated with higher rates of RDS (RR 1.15, 95% CI 1.08, 1.22) and assisted ventilation (RR 1.16, 95% CI 1.08, 1.24). CONCLUSION: Although labor was associated with a slightly higher mortality rate in SGA infants and slightly more respiratory morbidity in non-SGA infants, recommendations regarding clinical treatment should await future clinical trials.     

Adequacy of prenatal care and neonatal mortality in infants born to mothers with and without antenatal high-risk conditions

BACKGROUND: Previous studies have found that inadequate prenatal care was associated with increased neonatal mortality in the general pregnant women. AIMS: To examine the association between adequacy of prenatal care and neonatal mortality in the presence and absence of antenatal high-risk conditions. METHODS: We conducted a retrospective cohort study of infants based on 1995-2000 vital statistics data in the USA. The relative risk for neonatal death associated with adequacy of prenatal care was estimated by multivariate logistic regressions with adjustment of confounding factors. RESULTS: Inadequate prenatal care was associated with increased neonatal mortality when pregnancies were complicated by anaemia, cardiac disease, lung disease, chronic hypertension, diabetes, renal disease, pregnancy-induced hypertension, and previous preterm/small-for-gestational-age birth. The observed association also existed in the absence of these antenatal high-risk conditions. Overutilisation of prenatal care was associated with increased risk of neonatal deaths in both the presence and the absence of antenatal high-risk conditions. When gestational age at delivery and birthweight were further adjusted, the observed association between inadequate prenatal care and neonatal mortality was not significant in pregnancies with various high-risk conditions. CONCLUSIONS: Inadequate prenatal care is associated with increased neonatal death in both the presence and the absence of antenatal high-risk conditions. The observed association between inadequate prenatal care and neonatal mortality may be mediated by increased risk of preterm delivery and low birthweight in these pregnancies. Overutilisation of prenatal care is associated with potential risks for fetal and neonatal development, leading to increased neonatal mortality.     

Placenta previa in singleton and twin births in the United States, 1989 through 1998: a comparison of risk factor profiles and associated conditions

OBJECTIVE: The purpose of this study was to compare risk factor profiles for placenta previa between singleton and twin live births. STUDY DESIGN: This cohort study was based on United States natality data files (1989 through 1998) and comprised 37,956,020 singleton births and 961,578 twin births. Women who were diagnosed with placenta previa were included only if they were delivered by cesarean delivery. Risk factors for placenta previa that were examined included sociodemographic (age, gravidity, education, marital status, and race), behavioral (prenatal care, smoking, and alcohol use), previous preterm birth, and medical and obstetric factors. Effect modification between maternal age and gravidity and the dose-response relationship with number of cigarettes smoked/day on placenta previa risk were also evaluated. RESULTS: The rate of placenta previa was 40% higher among twin births (3.9 per 1,000 live births, n = 3,793 births) than among singleton births (2.8 per 1,000 live births, n = 104,754 births). Comparison of risk factors for placenta previa between the singleton and twin births revealed fairly similar risk factor profiles. Compared with primigravid women <20 years old, the risk for placenta previa increased by advancing age and by increasing number of pregnancies among both singleton and twin births. The number of cigarettes smoked per day also showed a dose-response trend for placenta previa risk in the two groups. CONCLUSION: The increased rate of placenta previa among twin births underscores the need to monitor carefully such pregnancies with heightened suspicion and awareness for the development of this condition.     

Neonatal mortality and morbidity rates in late preterm births compared with births at term

OBJECTIVE: To analyze neonatal mortality and morbidity rates at 34, 35, and 36 weeks of gestation compared with births at term over the past 18 years at our hospital and to estimate the magnitude of increased risk associated with late preterm births compared with births later in gestation. METHODS: We performed a retrospective cohort study of births at our hospital over the past 18 years. The study included all liveborn singleton infants between 34 and 40 weeks of gestation and without anomalies that were delivered to women who received prenatal care in our hospital system. Neonatal outcomes for late preterm births were compared with those for infants delivered at 39 weeks. RESULTS: Late preterm singleton live births constituted approximately 9% of all deliveries at our hospital and accounted for 76% of all preterm births. Late preterm neonatal mortality rates per 1,000 live births were 1.1, 1.5, and 0.5 at 34, 35, and 36 weeks, respectively, compared with 0.2 at 39 weeks (P<.001). Neonatal morbidity was significantly increased at 34, 35, and 36 weeks, including ventilator-treated respiratory distress, transient tachypnea, grades 1 or 2 intraventricular hemorrhage, sepsis work-ups, culture-proven sepsis, phototherapy for hyperbilirubinemia, and intubation in the delivery room. Approximately 80% of late preterm births were attributed to idiopathic preterm labor or ruptured membranes and 20% to obstetric complications. CONCLUSION: Late preterm births are common and associated with significantly increased neonatal mortality and morbidity compared with births at 39 weeks. Preterm labor was the most common cause (45%) for late preterm births. LEVEL OF EVIDENCE: II.     

Reconciling the high rates of preterm and postterm birth in the United States

OBJECTIVE: Preterm and postterm birth rates are substantially higher in the United States than in Canada and other industrialized countries, although relative mortality at preterm compared with term gestation is considerably lower. We attempted to explain these differences based on differences in the method of gestational age estimation. METHODS: We used information on all live births in the United States and Canada for 1995-2002 and on singleton births and perinatal deaths for 1996-1999. Gestational age in Canada was based on the clinical estimate, whereas in the United States both menstrual-based and clinical estimates were used. RESULTS: In 2002, preterm (12.3%) and postterm birth (6.6%) rates in the United States were far higher than in Canada (7.6% and 1.0%, respectively) when U.S. rates were based on menstrual dates. Differences were reduced or abolished when U.S. rates were based on the clinical estimate of gestation (10.1% and 1.0%, respectively). In Canada, the rate ratio for perinatal death at preterm compared with term gestation was 27.8 (95% confidence interval [CI] 26.3-29.3), similar to that in the United States when gestation was based on the clinical estimate (rate ratio 26.5, 95% CI 26.1-26.9, P value for difference in rate ratios=.06) but not when based on menstrual dates (rate ratio 18.9, 95% CI 18.7-19.2, P<.001). CONCLUSION: Menstrual dates in U.S. data misclassify gestational duration and overestimate both preterm and postterm birth rates. For international comparisons, gestational age in the United States should be based on the clinical estimate. Level of Evidence: II.     

Pregnancy-induced hypertension is associated with lower infant mortality in preterm singletons

OBJECTIVE: To assess the association between pregnancy-induced hypertension (PIH) and infant mortality. DESIGN: Retrospective cohort study. SETTING: Birth and infant death registration dataset of the USA. POPULATION: A total of 17,432,987 eligible, liveborn singleton births in 1995-2000. METHODS: Multivariate logistic regression was applied to evaluate the association between PIH and infant mortality, with adjustment of potential confounders. MAIN OUTCOME MEASURES: Infant death (0-364 days) and its three components: early neonatal death (0-6 days), late neonatal death (7-27 days), and postneonatal death (28-364 days). RESULTS: There was a significant reduction in infant mortality associated with PIH in early preterm infants (OR = 0.59, 95% CI: 0.56-0.63) and in late preterm infants (OR = 0.80, 95% CI: 0.73-0.87), but a significant increase in term infants (OR = 1.08, 95% CI: 1.02-1.14). Both in early preterm and late preterm births, early neonatal mortality (OR = 0.38, 95% CI: 0.34-0.42; OR = 0.68, 95% CI: 0.61-0.77) and late neonatal mortality (OR = 0.59, 95% CI: 0.50-0.70; OR = 0.76, 95% CI: 0.61-0.96) were decreased in infants born to mothers with PIH compared with those born to mothers with normal blood pressure. The PIH-associated reduction in neonatal mortality among preterm singletons was stronger in small-for-gestational-age infants than in normal growth infants and stronger in infants born to nulliparous women than in those born to multiparous women. CONCLUSIONS: PIH is associated with lower risk of infant death in preterm births but higher risk in term births.     

Maternal and obstetric risk factors for sudden infant death syndrome in the United States

OBJECTIVE: The objectives of this study were to 1). study the incidence of sudden infant death syndrome (SIDS) among singleton births in the United States and 2). identify maternal and obstetric risk factors for SIDS. METHODS: A cohort of all live births in the United States from 1995 to 1998, formed the source population (n = 15627404). The data were obtained from the National Centers for Health Statistics Linked Births and Infant Deaths File. A nested case-control study was used to examine risk factors for SIDS. From this birth cohort, all SIDS deaths (n = 12404) were first identified (case group). From the remaining non-SIDS births, a 4-fold larger sample (n = 49616) was randomly selected as a control group. RESULTS: The overall incidence of SIDS was 81.7 per 100000 live births. More mothers in the case group than in the control group were reported to have placenta previa (odds ratio [OR]: 1.70; 95% confidence interval [CI] 1.24, 2.33), abruptio placentae (OR 1.57; 95% CI 1.24, 1.98), premature rupture of membranes (OR 1.48; 95% CI 1.33, 1.66), or small for gestational age (OR 1.40; 95% CI 1.30, 1.50 for the 10th percentile). SIDS cases were also more likely to be male. Mothers of cases were more likely to be younger, less educated, and nonwhite, and more of them smoked during pregnancy and did not attend prenatal care. CONCLUSION: This analysis confirms the importance of several well known demographic and lifestyle risk factors for SIDS. In addition, placental abnormalities were risk factors for SIDS. LEVEL OF EVIDENCE: II-2     

Lack of prenatal care in a traditional society. Is it an obstetric hazard?

OBJECTIVE: To examine the association between lack of prenatal care (fewer than three visits at any prenatal care facility) and perinatal complications in the Bedouin parturient population where lack of prenatal care is not associated with absence of prenatal services, substance abuse or marital status. STUDY DESIGN: The study population consisted of all Bedouin women lacking prenatal care (n = 7,601) who gave birth between the years 1990-1997 in the Soroka University Medical Center. The analysis consisted of a comparison of labor and delivery outcomes in women without prenatal care to outcomes in women who had some prenatal care. RESULTS: During the years 1990-1997 there were 36,281 singleton deliveries to Bedouin women at our institution. Of those, 20.9% did not receive prenatal care. Mothers in the no-prenatal-care group tended to be in the extremes of their reproductive cycles (< 18 years, > 35 years) and were of higher parity (P < .001) than those receiving prenatal care. There were more deliveries prior to 32 weeks of gestation in the no-prenatal-care group (2.8%) in comparison to the prenatal care group (1.5%, P < .001) and fewer postterm deliveries (> 42 weeks, P < .01). The incidence of low birth weight (< 2,500 g) in the no-prenatal-care group was higher than in the prenatal-care group (11.2% vs. 8.4%, P < .001). Women who did not receive adequate prenatal care had statistically significantly higher rates of antepartum fetal death (OR = 1.8, 95% CI 1.4-2.3, P < .001), intrapartum fetal death (OR = 2.38, 95% CI 1.2-4.5, P < .03) and postpartum fetal death (OR = 1.60, 95% CI 1.2-2.1, P < .001). Multiple logistic regression models were used to analyze the independent contribution of lack of prenatal care to perinatal mortality and to very-low-birth-weight newborns. In both models lack of prenatal care was an independent contributing factor. CONCLUSION: Lack of prenatal care is an independent contributor to perinatal mortality and low birth weight in a traditional society. In light of the high percentage of lack of prenatal care in Bedouin society, special attempts should be made to encourage women to use the available prenatal services.     

Triplet infants with birthweight < or = 1250 grams: how well do they compare with twin and singleton infants at 36 to 48 months of age?

The purpose of this study was to determine if triplet infants with birthweight < or = 1250 g were at increased risk of long-term disability compared with similar birthweight and gestational age singletons and twins. This was a retrospective cohort study of < or = 1250-g infants admitted to a regional neonatal intensive care unit from 1986 to 2001 with follow-up to 36 to 48 months corrected gestational age. Outcomes studied were cognitive ability, cerebral palsy, and neurosensory impairment at 36 to 48 months. Enrollment was 1717 infants: 59 triplets, 402 twins, and 1256 singletons. Triplet infants differed from twin or singleton infants because they were more likely to have older, married mothers (relative risk [RR] 3.62, 95% CI 1.31, 5.94), be products of assisted reproductive technology pregnancies (RR 29.59, 95% CI 13.97, 62.68), be exposed to antenatal steroids (RR 1.55, 95% CI 1.38, 1.75), and were all delivered by cesarean section. Triplet infants had lower risk of having intraventricular hemorrhage (RR 0.19, 95% CI 0.05, 0.75). The risk of cerebral palsy, cognitive delay, total major disability, or chronic lung disease was similar in triplet and twin infants compared with singleton infants. The lower risk of having intraventricular hemorrhage in triplet infants may have been due to the use of antenatal corticosteroids and cesarean section delivery.     

Fetal growth restriction and other factors associated with neonatal death in New Zealand

BACKGROUND: There are few studies of risk factors for neonatal death in Australia or New Zealand. AIMS: To assess in a cohort of neonatal deaths (i) the demographic and clinical risk factors; (ii) the relationship between low weight for gestation using population and customised centiles; and (iii) the cause of death by the Perinatal Society of Australia and New Zealand Perinatal and Neonatal death classifications. METHODS: A retrospective study of 410 babies who died, in the neonatal period, at National Women's Hospital, between 1993 and 2000. Demographic and clinical data were compared with that from a referent population of live births with neonatal deaths removed (n=68 905). RESULTS: The overall neonatal death rate was 5.9 per 1000 live births and after exclusion of congenital abnormalities was 3.9 per 1000 live births. Infants of Maori women had increased risk compared to European (adjusted odds ration (AOR) 1.52; 95% CI 1.06, 2.18), as did those born to primipara (AOR 1.52; 95% CI 1.10, 2.11), mothers with >or=1 previous low-birthweight baby (AOR 2.97; 95% CI 1.99, 4.44), >or=1 miscarriage (AOR 1.35; 95% CI 1.00, 1.81), and an index multiple pregnancy (AOR 10.51; 95% CI 8.04, 13.76). Infants of Chinese mothers had decreased risk (AOR 0.42; 95% CI 0.18, 0.96). Fifty (34%) babies were small for gestational age by customised and 26 (17%) by population centiles. The most common classification of neonatal death was congenital abnormality (34.6%), followed by extreme prematurity (34.1%). CONCLUSIONS: This study emphasises the importance of suboptimal fetal growth as an important risk factor for neonatal death especially when customised centiles are used.     

Outcomes of planned home births in Washington State: 1989-1996

OBJECTIVE: To determine whether there was a difference between planned home births and planned hospital births in Washington State with regard to certain adverse infant outcomes (neonatal death, low Apgar score, need for ventilator support) and maternal outcomes (prolonged labor, postpartum bleeding). METHODS: We examined birth registry information from Washington State during 1989-1996 on uncomplicated singleton pregnancies of at least 34 weeks' gestation that either were delivered at home by a health professional (N = 5854) or were transferred to medical facilities after attempted delivery at home (N = 279). These intended home births were compared with births of singletons planned to be born in hospitals (N = 10,593) during the same years. RESULTS: Infants of planned home deliveries were at increased risk of neonatal death (adjusted relative risk [RR] 1.99, 95% confidence interval [CI] 1.06, 3.73), and Apgar score no higher than 3 at 5 minutes (RR 2.31, 95% CI 1.29, 4.16). These same relationships remained when the analysis was restricted to pregnancies of at least 37 weeks' gestation. Among nulliparous women only, these deliveries also were associated with an increased risk of prolonged labor (RR 1.73, 95% CI 1.28, 2.34) and postpartum bleeding (RR 2.76, 95% CI 1.74, 4.36). CONCLUSION: This study suggests that planned home births in Washington State during 1989-1996 had greater infant and maternal risks than did hospital births.     

Relationship among placenta previa, fetal growth restriction, and preterm delivery: a population-based study

OBJECTIVE: To examine the independent contributions of prematurity and fetal growth restriction to low birth weight among women with placenta previa. METHODS: A population-based, retrospective cohort study of singleton live births in New Jersey (1989-93) was performed. Mother-infant pairs (n = 544,734) were identified from linked birth certificate and maternal and infant hospital discharge summary data. Women diagnosed with previa were included only if they were delivered by cesarean. Fetal growth, defined as gestational age-specific observed-to-expected mean birth weight, and preterm delivery (before 37 completed weeks) were examined in relation to previa. Severe and moderate categories of fetal smallness and large for gestational age were defined as observed-to-expected birth weight ratios below 0.75, 0.75-0.85, and over 1.15, respectively, all of which were compared with appropriately grown infants (observed-to-expected birth weight ratio 0.86-1.15). RESULTS: Placenta previa was recorded in 5.0 per 1000 pregnancies (n = 2744). After controlling for maternal age, education, parity, smoking, alcohol and illicit drug use, adequacy of prenatal care, maternal race, as well as obstetric complications, previa was associated with severe (odds ratio [OR] 1.37, 95% confidence interval [CI] 1.25, 1.50) and moderate fetal smallness (OR 1.24, 95% CI 1.17, 1.32) births. Preterm delivery was also more common among women with previa. Adjusted OR of delivery between 20-23 weeks was 1.81 (95% CI 1.24, 2.63), and 2.90 (95% CI 2.46, 3.42) for delivery between 24-27 weeks. OR for delivery by each week between 28 and 36 weeks ranged between 2.7 and 4.0. Approximately 12% of preterm delivery and 3.7% of growth restriction were attributable to placenta previa. CONCLUSION: The association between low birth weight and placenta previa is chiefly due to preterm delivery and to a lesser extent with fetal growth restriction. The risk of fetal smallness is increased slightly among women with previa, but this association may be of little clinical significance.